During mining and other bulk transport operations, material must be transported over long distances in order to load the material by truck or rail. Further, such material must be unloaded and transported for processing. Among the common means for transport are bulk conveyors which are capable of transporting large amounts of material quickly and reliably and without significant cost. Typical conveyors that may be employed include drag, screw, belt and pneumatic conveyors.
Belt conveyors are well suited for use in many transport applications and are particularly well suited for use in mining operations. Belt conveying systems include at least two pulleys and a conveyor belt which rotates about the two pulleys. Material is loaded onto the belt at a tail section and is unloaded via gravity at a head section. A tail pulley and head pulley allow the belt to travel from the point at which material is loaded to the point it is unloaded and back again. The conveying system may also include take-up pulleys to provide proper belt tensioning, bend pulleys to change the direction of travel of the belt and snub pulleys, typically located adjacent the drive pulley, to increase the contact with the drive pulley and/or provide belt tensioning. The belt may be driven at a number of positions including the tail section or head section of the conveyor system.
As the belt travels over the tail pulley in the tail section for loading of bulk material, the profile of the belt changes from a flat profile to a troughed profile in which the sides of the belt are raised to capture bulk material within the belt. Changing the profile of the belt creates stress along the belt. To reduce stress, the profile of the belt is changed incrementally from the tail pulley by use of several transition idlers.
A need exists for idler systems that increase the trough angle of the conveyor belt over relatively short distances without creating undue stress on the conveyor belt.
This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the disclosure, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.